Jack and plug type of electrical connector



A. LIEBSCHER JACK AND PLUG TYPE OF ELECTRICAL CONNECTOR Filed Aug. 21. 1945 Gttomeg Patented Oct. 14, 1947 JACK AND PLUG TYPE F ELECTRICAL- CONNECTOR Arthur Liebscher, Philadelphia, ra.;y assigner to Radio Corporation ot of Delaware- America, a corporation Application August 21, 194s, serial No. ias-,521 1 claim. (ci 113-363) This invention relates to electrical connectors.. and particularly to improvements vin connectors of the jack-and-plug (or pin) type.

It is common practice to employ jack-and-plug type connectors in Lest equipment and other apparatus wherein the connections are subjectlto frequent change. Such connectors, however, are not always desirable since the cords to which the plugs are attached may introduce electrical losses which result in false readings. In such cases the ing spring metaljaws I3 which are biased to enpreferred practice. has been to provide auxiliary y binding posts as connectors used for making measusements involving the resistive properties of the device under test. This duplication of both male and female connectors necessitates 'the use of additional internal wiring and therefore contributes materially to the complexity and cost of the equipment.

Accordingly, it is an object of the present invention to provide a combined binding post and pin jack connector.

Another and important object of the inventionis to Iprovide an improved Jack adapted to receive either a plug (or pin) or a binding post and one capable of retaining the said plug. Din or post either in locked or unlocked engagement.

A related object of the present invention is to provide an improved solderless plug type connector which is capable of being locked within the jack, and one nevertheless characterized by the simplicity and economy of its parts.

Other objects and advantages will be apparent and the invention itself will be best understood by reference to the following speciiication and tothe accompanying drawing, wherein Fig. 1 is a sectional elevation of a plug connector comprising a jack and a removable binding post, constructed in accordance with the principle of the invention and showing the binding post in its unlocked position within the jack,

Fig. 2 is a sectional elevation of the device of Fig. 1 showing the binding post in its locked position,

Fig. 3 is a cross-section view taken on the line 3-3 of Fig. 1, and

Fig. 4 is a sectional elevation of an alternative form of plug for use with the jack of Figs. 1v

and 2.

In the jack and binding post assembly shown in Figs. 1 to 3, inclusive, the jack I comprises a molded tubular shell constituted of insulating material and is shown clamped to a panel 3 by means of a conventional lock washer 5 and nut 1. The bore of the jack is designated 9; it contains a tubular or equivalent type of conductor II hav- .gage at least the leading portion of the rod, pin

or plug 'I5 of the binding post or other connector I v'which it is designed to serve.

This more or less standard jack I .is provided. in accordance with the invention, with an internally threaded annuius or nut I'I which is immovably embedded in thehead of the jack slightly beneath the plane of its outer face I9 and surrounding the axis of the bore 9. The internal diameter of this nut I1 is substantially greater than the diameter of the plug I5 so that the leading end of the plug may be readily'passed therey' through into and out of engagement with the jaws I3 of the spring hereinafter more uily appear, this internally threaded insert I'I cooperates with a complementarily threaded nxture 2i on the plug I5 whenever it is desired to lock" the plug within the jack.

As in standard practice. the binding post portion of the plug shown of Figs. 1 and 2 is provided with a hole 23 for receiving a wire or other external lead, not shown. A captive head or knob 25 on one side of the hole 23 and an immovable -ange or rim 21 on the plug side of the hole comprise opposing surfaces between which the said external lead is clamped when the head 25 is. screwed down on the post. The externally threaded part 2| which engages the internallythreaded embedded nut I'I (when the plug is inserted suniciently far into the bore of the jack) is on the plug side of the flange 21 and, like the said ange, is secured against rotation on and with respect` to the plug. It will be observed that `flange 21 is knurled as indicated at 29 on the side' which faces the jack and this knurled or roughened face 29 is `brought'into positive fric'- tional engagement with the non-metallic surface I9of the jack when the iixture or sleeve 2|' on the trailing end of the prong I5 is screwed up on the nut I1 by turning the knob 25 as far as it will go inthe clockwise direction. When the knob or head 25 is turned `in the counter-clockwise directionrthe knurled face 29 of the iiange 2'IA remains' in engagement with the face I9 of the jack until the hole 23 in the binding post is exposed. This permits the connector in the said hole to be changed without removing the plug from the jack. The application of a lslightly greater torque to the knob 25 than is required to expose the laperture 23 causes the plug I5 and the threaded sleeve 2I thereon to be turned within the jack and with respect to the embedded nut etal connector II. As will I'l so that, when the said sleeve is unscrewed. the plug can be pulled out of the jack.

Fig. 4 shows a standard cord-type connector which has been modiiled in accordance with the invention to provide means for locking it within the bore of the/jack of Figs. 1 and 2. The connector here illustrated comprises an fouter insulating cylinder 3| and an inner hollow metal cylinder 33 which extends beyond the end of the e insulating cylinder 3i and terminates in a solid rod-like plug 35, which is provided adjacent to its trailing end with an integral externally threaded fixture 31 upon which a hollow cap 33 having complementary internal threads is mounted. To apply this plug to a cord or wire-(not shown), the end oi the cord is entered into the open ends of the cylinders 3l and 33 and passed through an aperture 4I in the exposed end of the 'inner cylinder 33, whereupon the cap 39 is Vscrewed down on the threaded portion 31 oi' the plug to cover the said connection. In accordance with the present invention, the xture l3`| on the plug or this otherwise standard connector is made sumciently long to permit it to be entered into the threaded nut I1 which is embedded in the Jack i (Figs. 1 and 2) and its diameter and threads are so dimensioned that the said nxture cooperates with said nut to secure the plug within the bore of the jack in the manner previously described.

From the foregoing it will be apparent that the present invention provides an improved jackand-plug type connector wherein the Jack is adapted to receive either a plug, or pin, or bind-` ing post and is capable' of retaining the said plug, 35 2,049,749

pin or post either What is claimed is:

In combination, a jack comprising a body portion constituted of insulating material and having a bore adapted to receive a. plug. a conductive connector for said plug mounted within -said bore, an annulus having an internally threaded surface oi a diameter greater than that of said plug embedded beneath the face of said insulating material adjacent to the entrance of said bore, a plug having a captive head on its trailing end and a leading rod-like portion adapted to be thrust into said bore through said annulus into engagement with said connector, a threaded projection on the outer end of said rod-like por- 1tion i'or engagement with said internally threaded annulus, and a ange intermediate said threaded projectionA and said captive head, said flange having a knurled surface on the side iacing said jack and adapted to be brought into frictional engagement withthe said insulating face oi said jack when said plug is rotated to bring v its said threaded projection into engagement with said internally threaded annulus.

ARTHUR LIEBSCHER.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name ADate 2,253,223 Blake Aug. 19, 1941 1,168,019 Liversidge Jan. 11, 1916 Roth Aug. 4, 1936 2,253,223 Blake Aug. 19, 1941 1,653,029 Yaxley Dec. 20, 1927 

